Pub Date : 2023-04-03DOI: 10.1080/0269249X.2023.2233515
David M. Williams
The case of Synedra pelagica Hendey is discussed in terms of its nomenclature, the taxonomic implications of priority issues and its characterization. Application of replacement names for specific epithets is reasonably straightforward as it is governed by the ICN – conditions for valid publication of any taxonomic name can be satisfied even if no one can subsequently identify the taxon. The lack of clear diagnostic characters, as opposed to a description, can obscure what the name actually represents. These issues are briefly discussed with Synedra pelagica in mind.
{"title":"Names, diagnoses and ‘Dead Names’: the case of Synedra pelagica","authors":"David M. Williams","doi":"10.1080/0269249X.2023.2233515","DOIUrl":"https://doi.org/10.1080/0269249X.2023.2233515","url":null,"abstract":"The case of Synedra pelagica Hendey is discussed in terms of its nomenclature, the taxonomic implications of priority issues and its characterization. Application of replacement names for specific epithets is reasonably straightforward as it is governed by the ICN – conditions for valid publication of any taxonomic name can be satisfied even if no one can subsequently identify the taxon. The lack of clear diagnostic characters, as opposed to a description, can obscure what the name actually represents. These issues are briefly discussed with Synedra pelagica in mind.","PeriodicalId":11199,"journal":{"name":"Diatom Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46308434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-02DOI: 10.1080/0269249X.2022.2159883
K. Abe, R. Jordan
A taxonomic survey of the early Eocene diatomites of Mors has revealed a new member of the Corethrales, Davidharwoodia megaspina gen. et sp. nov., which is the first fossil Corethron-like diatom to possess backward-pointing spines. The new species is presumably heterovalvate, with a rounded pyramidal Type 1 valve bearing a single huge leaf-shaped spine (and corresponding large socket) in addition to the narrower spines, and a more elongate helmet-shaped Type 2 valve possessing spines of a different design and twice as many sockets of equal size. The genus can be distinguished from Micrampulla by lacking the large inflated structures emanating from the dome, from Praecorethron by a narrower marginal area and vertically placed sockets, and from Corethron by lacking hooked spines.
对摩尔斯早始新世硅藻的分类调查发现了Corethrales的新成员Davidharwoodia megaspina gen. et sp. nov.，这是第一个具有后指向棘的corethron类硅藻化石。这个新物种可能是异瓣形的，除了较窄的刺外，还有一个圆形的金字塔形的1型阀，它有一个巨大的叶形刺(和相应的大凹槽)，一个更长的盔形2型阀，它有一个不同设计的刺和两倍大小的凹槽。该属与Micrampulla的区别在于缺乏从穹顶中产生的大型膨胀结构，与preecorethron的区别在于有较窄的边缘区域和垂直放置的窝，与Corethron的区别在于缺乏钩状刺。
{"title":"Davidharwoodia megaspina gen. et sp. nov. (Corethrales), a new fossil marine diatom genus from Mors, Jutland (early Eocene)","authors":"K. Abe, R. Jordan","doi":"10.1080/0269249X.2022.2159883","DOIUrl":"https://doi.org/10.1080/0269249X.2022.2159883","url":null,"abstract":"A taxonomic survey of the early Eocene diatomites of Mors has revealed a new member of the Corethrales, Davidharwoodia megaspina gen. et sp. nov., which is the first fossil Corethron-like diatom to possess backward-pointing spines. The new species is presumably heterovalvate, with a rounded pyramidal Type 1 valve bearing a single huge leaf-shaped spine (and corresponding large socket) in addition to the narrower spines, and a more elongate helmet-shaped Type 2 valve possessing spines of a different design and twice as many sockets of equal size. The genus can be distinguished from Micrampulla by lacking the large inflated structures emanating from the dome, from Praecorethron by a narrower marginal area and vertically placed sockets, and from Corethron by lacking hooked spines.","PeriodicalId":11199,"journal":{"name":"Diatom Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45229899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-02DOI: 10.1080/0269249X.2023.2215110
Adil Y. AL-HANDAL, Maja Mucko, P. Peharec Štefanić, A. Wulff
The diatom genus Entomoneis includes species with panduriform frustules characterized by a bilobate, elevated keel, sigmoid raphe canal and numerous open, porous girdle bands. During a phytoplankton survey along the Baltic coast of Sweden, we observed numerous Entomoneis cells, some belonging to the well-known Entomoneis paludosa, while others remained unknown. Morphological and ultrastructural studies of the unknown species were performed with light microscopy (LM), scanning (SEM) and transmission (TEM) electron microscopy, and revealed a unique set of morphological characters. Live cells of Entomoneis grisslehamnensis sp. nov. contain one plate-like plastid and show various degrees of torsion about the apical axis. Microscopic features of cleaned frustules are discussed in comparison with similar species. Most importantly, every 2nd to 5th virga is strongly elevated, uniseriate striae are composed of quadrangular areolae with finely perforated hymenes; the winged keel with a discernible raphe canal is structurally strengthened by raphe fibulae with a flattened wing area, and the main part of the valve bulges towards the margins; striation is decussate on the wings and there is one row of raphe canal areolae at the central area. In addition to describing this new species of an underappreciated, yet cosmopolitan diatom genus, we contribute to the taxonomy of E. paludosa with LM, SEM and TEM details, some of which were not sufficiently noted in original descriptions or re-examination of type material and other specimens made by Dalu et al. [2015. A re-examination of the type material of Entomoneis paludosa (W. Smith) Reimer and its morphology and distribution in African waters. Fottea 15: 11–25] and Long et al. [2022. Ultrastructure of three species of Entomoneis (Bacillariophyta) from Lake Qinghai of China, with reference to the external areola occlusions. PhytoKeys 189: 29–50. doi:10.3897/phytokeys.189.78149].
{"title":"Entomoneis grisslehamnensis, a New Diatom (Bacillariophyceae) from the Baltic Coast of Sweden with taxonomic and ecological notes on Entomoneis paludosa (W. Smith) Reimer","authors":"Adil Y. AL-HANDAL, Maja Mucko, P. Peharec Štefanić, A. Wulff","doi":"10.1080/0269249X.2023.2215110","DOIUrl":"https://doi.org/10.1080/0269249X.2023.2215110","url":null,"abstract":"The diatom genus Entomoneis includes species with panduriform frustules characterized by a bilobate, elevated keel, sigmoid raphe canal and numerous open, porous girdle bands. During a phytoplankton survey along the Baltic coast of Sweden, we observed numerous Entomoneis cells, some belonging to the well-known Entomoneis paludosa, while others remained unknown. Morphological and ultrastructural studies of the unknown species were performed with light microscopy (LM), scanning (SEM) and transmission (TEM) electron microscopy, and revealed a unique set of morphological characters. Live cells of Entomoneis grisslehamnensis sp. nov. contain one plate-like plastid and show various degrees of torsion about the apical axis. Microscopic features of cleaned frustules are discussed in comparison with similar species. Most importantly, every 2nd to 5th virga is strongly elevated, uniseriate striae are composed of quadrangular areolae with finely perforated hymenes; the winged keel with a discernible raphe canal is structurally strengthened by raphe fibulae with a flattened wing area, and the main part of the valve bulges towards the margins; striation is decussate on the wings and there is one row of raphe canal areolae at the central area. In addition to describing this new species of an underappreciated, yet cosmopolitan diatom genus, we contribute to the taxonomy of E. paludosa with LM, SEM and TEM details, some of which were not sufficiently noted in original descriptions or re-examination of type material and other specimens made by Dalu et al. [2015. A re-examination of the type material of Entomoneis paludosa (W. Smith) Reimer and its morphology and distribution in African waters. Fottea 15: 11–25] and Long et al. [2022. Ultrastructure of three species of Entomoneis (Bacillariophyta) from Lake Qinghai of China, with reference to the external areola occlusions. PhytoKeys 189: 29–50. doi:10.3897/phytokeys.189.78149].","PeriodicalId":11199,"journal":{"name":"Diatom Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43328032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-02DOI: 10.1080/0269249X.2023.2173308
Kensuke Toyoda, David M. Williams, E. Cox, Tanja M. Schuster
Kützing described the species Achnanthes capensis Kützing along with the variety Achnanthes capensis ß multiarticulata Kützing. The latter was based on ‘Achnanthes striata Suhr’, a name first mentioned, without description or figure, in Drège’s Zwei pflanzengeographische Documente. ‘Achnanthes striata’ became a synonym of Achnanthes capensis in Kützing’s protologue without it ever being validly published. All original specimens of Achnanthes capensis, A. capensis ß multiarticulata and A. striata are from Table Bay, Cape Province, Cape of Good Hope, South Africa. This account describes specimens from original material for all three names in Achnanthes and clarifies their relationships. As no morphological differences among these three named taxa could be found based on light and scanning electron microscopy observations, we place the other two names into A. capensis, as this name has priority. In short, A. capensis ß multiarticulata and A. striata are synonyms of Achnanthes capensis.
{"title":"Studies on type material from Kützing’s diatom collection VII: Achnanthes capensis Kützing, Achnanthes capensis ß [var.] multiarticulata Kützing and ‘Achnanthes striata Suhr’","authors":"Kensuke Toyoda, David M. Williams, E. Cox, Tanja M. Schuster","doi":"10.1080/0269249X.2023.2173308","DOIUrl":"https://doi.org/10.1080/0269249X.2023.2173308","url":null,"abstract":"Kützing described the species Achnanthes capensis Kützing along with the variety Achnanthes capensis ß multiarticulata Kützing. The latter was based on ‘Achnanthes striata Suhr’, a name first mentioned, without description or figure, in Drège’s Zwei pflanzengeographische Documente. ‘Achnanthes striata’ became a synonym of Achnanthes capensis in Kützing’s protologue without it ever being validly published. All original specimens of Achnanthes capensis, A. capensis ß multiarticulata and A. striata are from Table Bay, Cape Province, Cape of Good Hope, South Africa. This account describes specimens from original material for all three names in Achnanthes and clarifies their relationships. As no morphological differences among these three named taxa could be found based on light and scanning electron microscopy observations, we place the other two names into A. capensis, as this name has priority. In short, A. capensis ß multiarticulata and A. striata are synonyms of Achnanthes capensis.","PeriodicalId":11199,"journal":{"name":"Diatom Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46763974","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-02DOI: 10.1080/0269249X.2023.2208136
Marina G. Potapova, Micaela H. Kersey, Laura L. Aycock
Six species of large-celled Pinnularia Ehrenberg from lakes of eastern North America, P. dariana (A.W.F. Schmidt) Mills, P. alabamae Krammer, P. bihastata (A. Mann) R.M. Patrick, P. torta (A. Mann) R.M. Patrick, P. rexlowei sp. nov. and P. spinifera sp. nov. are investigated with light and scanning electron microscopy. All six species are shown to possess marginal spines, a trait sporadically encountered in Pinnularia and generally rare in raphid diatoms. Besides having spines, the six species differ in their frustular morphology, including appearance and position of spines. We summarize data on their ecology and distribution using a set of 702 sediment core samples from 424 lakes from eastern USA and Canada. Pinnularia rexlowei is only known from Quaternary lacustrine deposits in the State of Connecticut and from the surface and subfossil sediments of two lakes in northeastern USA. The other five species are relatively common, and at least one species of spine-bearing Pinnularia was found in 34% of studied lakes. Pinnularia dariana and P. torta reach as far north as Labrador, while P. alabamae, P. bihastata and P. spinifera were only encountered south of Canada. Pinnularia alabamae and P. spinifera are characteristic for lakes with relatively soft and slightly acidic water, while P. bihastata, P. dariana and P. torta are found in a wider range of physico-chemical conditions, including alkaline and eutrophic lakes.
{"title":"Diversity and distribution of spine-bearing species of Pinnularia in eastern North America","authors":"Marina G. Potapova, Micaela H. Kersey, Laura L. Aycock","doi":"10.1080/0269249X.2023.2208136","DOIUrl":"https://doi.org/10.1080/0269249X.2023.2208136","url":null,"abstract":"Six species of large-celled Pinnularia Ehrenberg from lakes of eastern North America, P. dariana (A.W.F. Schmidt) Mills, P. alabamae Krammer, P. bihastata (A. Mann) R.M. Patrick, P. torta (A. Mann) R.M. Patrick, P. rexlowei sp. nov. and P. spinifera sp. nov. are investigated with light and scanning electron microscopy. All six species are shown to possess marginal spines, a trait sporadically encountered in Pinnularia and generally rare in raphid diatoms. Besides having spines, the six species differ in their frustular morphology, including appearance and position of spines. We summarize data on their ecology and distribution using a set of 702 sediment core samples from 424 lakes from eastern USA and Canada. Pinnularia rexlowei is only known from Quaternary lacustrine deposits in the State of Connecticut and from the surface and subfossil sediments of two lakes in northeastern USA. The other five species are relatively common, and at least one species of spine-bearing Pinnularia was found in 34% of studied lakes. Pinnularia dariana and P. torta reach as far north as Labrador, while P. alabamae, P. bihastata and P. spinifera were only encountered south of Canada. Pinnularia alabamae and P. spinifera are characteristic for lakes with relatively soft and slightly acidic water, while P. bihastata, P. dariana and P. torta are found in a wider range of physico-chemical conditions, including alkaline and eutrophic lakes.","PeriodicalId":11199,"journal":{"name":"Diatom Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46563734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-02DOI: 10.1080/0269249X.2022.2154280
K. Abe, R. Jordan
Pyxilla? dubia was originally described from Jutland, but subsequently transferred to Pseudopyxilla. However, the discovery, over eighty years apart, of two enigmatic specimens with tubular heterovalvate frustules featuring a Pseudopyxilla dubia valve at one end and a rhizosolenioid valve at the other end resulted in a new combination, Rhizosolenia dubia. Herein, we document in detail the valve morphology of specimens observed in early Eocene samples from Mors (Jutland) using light and scanning electron microscopy. Our results reveal the presence of both valve types (but never as heterovalvate frustules). The rhizosolenioid valves possess a proboscis with three spinulae at the tip (the middle one being very extensive), a longitudinal slit on the dorsal side, and claspers on the basal part of the domed valve on the ventral side. Our results suggest that the Pseudopyxilla frustule is the resting spore of a yet, unknown diatom, while the ‘rhizosolenioid’ valve represents the vegetative phase of a new species, Proboscia pinocchioi sp. nov. From an evolutionary standpoint, P. pinocchioi lacks the longitudinal ridges of the cretacea lineage, but bears the characteristic polar spinulae and limited pore distribution of the barboi lineage. However, P. pinocchioi surprisingly possesses claspers (normally observed only in the alata lineage) – representing the oldest evidence of claspers in rhizosolenioid diatoms.
{"title":"On the enigmatic diatom Rhizosolenia dubia, its relationship to Pseudopyxilla and Proboscia, and description of a new species, Proboscia pinocchioi sp. nov.","authors":"K. Abe, R. Jordan","doi":"10.1080/0269249X.2022.2154280","DOIUrl":"https://doi.org/10.1080/0269249X.2022.2154280","url":null,"abstract":"Pyxilla? dubia was originally described from Jutland, but subsequently transferred to Pseudopyxilla. However, the discovery, over eighty years apart, of two enigmatic specimens with tubular heterovalvate frustules featuring a Pseudopyxilla dubia valve at one end and a rhizosolenioid valve at the other end resulted in a new combination, Rhizosolenia dubia. Herein, we document in detail the valve morphology of specimens observed in early Eocene samples from Mors (Jutland) using light and scanning electron microscopy. Our results reveal the presence of both valve types (but never as heterovalvate frustules). The rhizosolenioid valves possess a proboscis with three spinulae at the tip (the middle one being very extensive), a longitudinal slit on the dorsal side, and claspers on the basal part of the domed valve on the ventral side. Our results suggest that the Pseudopyxilla frustule is the resting spore of a yet, unknown diatom, while the ‘rhizosolenioid’ valve represents the vegetative phase of a new species, Proboscia pinocchioi sp. nov. From an evolutionary standpoint, P. pinocchioi lacks the longitudinal ridges of the cretacea lineage, but bears the characteristic polar spinulae and limited pore distribution of the barboi lineage. However, P. pinocchioi surprisingly possesses claspers (normally observed only in the alata lineage) – representing the oldest evidence of claspers in rhizosolenioid diatoms.","PeriodicalId":11199,"journal":{"name":"Diatom Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59426376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-02DOI: 10.1080/0269249X.2022.2141345
D. Winter, T. Yancey
A new Paralia Heiberg species, Paralia flatoniana sp. nov., is documented from a late Eocene diatomite and mudstone deposit in east central Texas. Paralia represents up to 63% of the assemblage in the diatomite samples and 34% in the mudstone. Numerous Paralia initial valves are present adding an unusual component to this assemblage as they are infrequently reported from samples containing populations of fossil Paralia. A third valve type observed attached to Paralia chains is also illustrated and discussed. Intact chains are common and preservation of the frustules is very good with limited indication of dissolution or transport. An average valve diameter of 19.0 µm (7.1–37.7 µm range), the presence of numerous initial valves and preservation of fine morphological structures suggest an environment with often high in situ productivity rather than a transported assemblage. Morphologically similar species Paralia crenulata and Paralia thybergii share many mantle characteristics with P. flatoniana while the valve face details of Paralia fausta are similar. Paleogeography and – ecology of the Eocene Gulf of Mexico and volcanism to the west provided a temperate coastal nutrient-rich shelf environment favourable for Paralia.
{"title":"Paralia flatoniana sp. nov., a new species from the late Eocene of Texas with discussion on ecology and initial valves","authors":"D. Winter, T. Yancey","doi":"10.1080/0269249X.2022.2141345","DOIUrl":"https://doi.org/10.1080/0269249X.2022.2141345","url":null,"abstract":"A new Paralia Heiberg species, Paralia flatoniana sp. nov., is documented from a late Eocene diatomite and mudstone deposit in east central Texas. Paralia represents up to 63% of the assemblage in the diatomite samples and 34% in the mudstone. Numerous Paralia initial valves are present adding an unusual component to this assemblage as they are infrequently reported from samples containing populations of fossil Paralia. A third valve type observed attached to Paralia chains is also illustrated and discussed. Intact chains are common and preservation of the frustules is very good with limited indication of dissolution or transport. An average valve diameter of 19.0 µm (7.1–37.7 µm range), the presence of numerous initial valves and preservation of fine morphological structures suggest an environment with often high in situ productivity rather than a transported assemblage. Morphologically similar species Paralia crenulata and Paralia thybergii share many mantle characteristics with P. flatoniana while the valve face details of Paralia fausta are similar. Paleogeography and – ecology of the Eocene Gulf of Mexico and volcanism to the west provided a temperate coastal nutrient-rich shelf environment favourable for Paralia.","PeriodicalId":11199,"journal":{"name":"Diatom Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44925868","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-02DOI: 10.1080/0269249X.2022.2141346
Heba Mohamad, Demetrio Mora, O. Skibbe, Nélida Abarca, Verena Deutschmeyer, N. Enke, Wolf-Henning Kusber, J. Zimmermann, R. Jahn
Monoclonal diatom strains are the basis for integrative taxonomical studies combining molecular and morphological data for better taxonomic resolution and identification. The identification of diatoms, based on morphological features of the frustule, is difficult due to the variability of characters within and amongst species. The longer the cultivation time, the more cell size is reduced during asexual reproduction. Many divisions of the cell complicate identification as morphological characters of the frustule change at different rates in different taxa and teratologies can develop. Morphological variability raises the question whether the investigated genetic markers are stable over the cultivation time span. Sixteen monoclonal pennate diatom strains, identified as 10 different species in six genera, were cultivated for up to 18 or 24 months. It was shown that molecular data for the 18S-V4, rbcL, and psbA markers were stable for the entire cultivation time of all taxa. Images of the valves of the strains were taken every six months and examined morphometrically. Depending on the time since the start of the cultures, the morphological features showed high variability, particularly in length and shape, whereas width and number of striae, costae or fibulae were more stable, depending on the taxon and strain. A limited time span and good culture conditions seem to be prerequisite to avoid the production of teratological frustules. The results of parallel cultures in a unique experimental design are compared to observations from the literature dealing with single strains or special cognitive interests.
{"title":"Morphological variability and genetic marker stability of 16 monoclonal pennate diatom strains under medium-term culture","authors":"Heba Mohamad, Demetrio Mora, O. Skibbe, Nélida Abarca, Verena Deutschmeyer, N. Enke, Wolf-Henning Kusber, J. Zimmermann, R. Jahn","doi":"10.1080/0269249X.2022.2141346","DOIUrl":"https://doi.org/10.1080/0269249X.2022.2141346","url":null,"abstract":"Monoclonal diatom strains are the basis for integrative taxonomical studies combining molecular and morphological data for better taxonomic resolution and identification. The identification of diatoms, based on morphological features of the frustule, is difficult due to the variability of characters within and amongst species. The longer the cultivation time, the more cell size is reduced during asexual reproduction. Many divisions of the cell complicate identification as morphological characters of the frustule change at different rates in different taxa and teratologies can develop. Morphological variability raises the question whether the investigated genetic markers are stable over the cultivation time span. Sixteen monoclonal pennate diatom strains, identified as 10 different species in six genera, were cultivated for up to 18 or 24 months. It was shown that molecular data for the 18S-V4, rbcL, and psbA markers were stable for the entire cultivation time of all taxa. Images of the valves of the strains were taken every six months and examined morphometrically. Depending on the time since the start of the cultures, the morphological features showed high variability, particularly in length and shape, whereas width and number of striae, costae or fibulae were more stable, depending on the taxon and strain. A limited time span and good culture conditions seem to be prerequisite to avoid the production of teratological frustules. The results of parallel cultures in a unique experimental design are compared to observations from the literature dealing with single strains or special cognitive interests.","PeriodicalId":11199,"journal":{"name":"Diatom Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48211347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-16DOI: 10.1080/0269249x.2022.2078428
D. Mann
{"title":"Determining geographical range and alien status in diatoms: three instructive case histories of species newly recorded in the British Isles, including a non-native marine species from the Pacific, Diademoides luxuriosa","authors":"D. Mann","doi":"10.1080/0269249x.2022.2078428","DOIUrl":"https://doi.org/10.1080/0269249x.2022.2078428","url":null,"abstract":"","PeriodicalId":11199,"journal":{"name":"Diatom Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46070145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-09DOI: 10.1080/0269249x.2022.2087742
J.P. Kociolek, D.M. Williams, A. Danz
We present the size diminution series of a new species of Tetracyclus, described herein as Tetracyclus stelloides Kociolek, D.M.Williams & Danz sp. nov., based on light and scanning electron microscopic observations. The largest cells of T. stelloides sp. nov. are cruciate in outline with broadly rounded apices and central inflations, the smallest cells are elliptical. Size, presence and position of a rimoportula, and valve shape differentiate this species from other described taxa in the genus. We discuss the ontogeny of this cell cycle in the context of Hustedt's concept of convergence and ‘miserable forms’. The taxonomic and nomenclatural implications of these findings for other species of Tetracyclus are discussed, and we explore the confusion and challenges related to the idea of ‘Accepted Names’ in this regard.
{"title":"Taxonomy and Valve Ultrastructure of New and Interesting Freshwater Fossil Diatoms (Bacillariophyta) of Miocene age from the Espanola Formation of New Mexico, USA. I. Ontogeny of Tetracyclus stelloides sp. nov., with Comments on ‘Accepted Names’ and Hustedt's Concepts of ‘Convergence’ and ‘Miserable Forms’","authors":"J.P. Kociolek, D.M. Williams, A. Danz","doi":"10.1080/0269249x.2022.2087742","DOIUrl":"https://doi.org/10.1080/0269249x.2022.2087742","url":null,"abstract":"<p>We present the size diminution series of a new species of <i>Tetracyclus</i>, described herein as <i>Tetracyclus stelloides</i> Kociolek, D.M.Williams & Danz sp. nov., based on light and scanning electron microscopic observations. The largest cells of <i>T. stelloides</i> sp. nov. are cruciate in outline with broadly rounded apices and central inflations, the smallest cells are elliptical. Size, presence and position of a rimoportula, and valve shape differentiate this species from other described taxa in the genus. We discuss the ontogeny of this cell cycle in the context of Hustedt's concept of convergence and ‘miserable forms’. The taxonomic and nomenclatural implications of these findings for other species of <i>Tetracyclus</i> are discussed, and we explore the confusion and challenges related to the idea of ‘Accepted Names’ in this regard.</p>","PeriodicalId":11199,"journal":{"name":"Diatom Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138536262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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